(1) Field of Invention
The present invention relates to a wrench, and more particularly, to a wrench with a stepless mechanism for receiving and turning a slideable shaft in a desired direction.
(2) Description of Related Art
Wrench mechanisms have generally included a spring and pawl arrangement where the spring-biased pawl engages teeth of a driven gear. The pawl is arranged such that it is cammed away from the gear teeth upon rotation in one direction, but forced to engage with the gear when turned in the other direction.
While the spring and pawl arrangement is effective, it suffers from several inherent problems. For example, because of its ratcheting mechanism, there is considerable drag and friction between moving parts such as the pawl and gear. The friction can result in gear wear or breakage. Additionally, there is a significant amount of opposite or backward rotation before the pawl wedges into the gear teeth to immobilize the gear. While the backward rotation may only be a few degrees, this may be objectionable in certain applications.
A stepless wrench largely overcomes these problems. U.S. Pat. No. 1,412,688, issued to Layton and Hopkins, teaches using a wrench with friction gripping rollers. When in use, the friction gripping rollers allow the wrench to freely rotate around a shaft in one direction, but bind on the shaft when turned in the other direction. Although such stepless wrenches previously devised solve several of the problems inherent in the spring and pawl arrangement, they also suffer from several problems. While a shaft may be easily inserted into the stepless wrench, there is little to keep it from sliding out. Additionally, the previous stepless wrenches only accept the shaft perpendicularly to the handle, precluding a user from fitting the wrench into tight spaces by accepting the shaft parallel with the handle.
In light of the shortcomings of current wrenches discussed above, it can be appreciated that there exists a continuing need for a new and improved stepless wrench, where an inserted shaft stays affixed with the wrench and where the handle can also be manufactured to operate parallel to the inserted shaft. In this regard, the present invention substantially fulfills this need.